When over in the US recently - I saw advertised Z MAX engine/gearbox treatment with LINKITE - as used in the aviation industry - approved by various departments and guaranteed to give 10% fuel improvement - clean your engine and generally make your car last for years longer. They compared their system with the likes of Slick50 - slick50 being - well - snake oil - and theirs being the best thing since - well the best thing ever.Anyobe tried this?Does it do what it says??????